The invention concerns a multi-layer gasket or seal member.
In particular the invention relates to a gasket or seal member for use in a flanged joint subject to a pressure differential. For example the kind of joint found between gas turbine engine casing sections. However, the invention will find wider use to seal flanged joints between duct and casing sections generally, or anywhere else where plain face-to-face seals are presently used.
Flanged joints are commonly used to join casing and duct sections together, as well as pipe lengths. Where a fluid tight seal is required some form of gasket or seal member is interposed between the flanges. The most common type of seal is a plain face-to-face seal made of resilient or elastic material, capable of withstanding sustained contact with the contained fluid and the fluid pressure. Flanges are effective seats for face-to-face seals providing the flange faces are machined substantially flat, and remain so in use. However, such joints are liable to suffer leakage problems if the flanges are not stiff enough to avoid significant distortion effects at the joint interface arising from relative flexing of the components on either side of the joint.